An internet search indicates:
The Clark CMP 18L is a propane (LPG) powered pneumatic tire forklift, with production models spanning from roughly 1998 to 2010. It is designed for indoor and outdoor use, with a capacity of roughly 1.8 tons (approximately 3,500 - 4,000 lbs, depending on specific configuration).
Key Features and Specifications:
Engine: Typically powered by LPG (Liquid Propane Gas).
Capacity: Nominal load capacity at the center of gravity is 1.8 metric tons (approx. 3,968 lbs).
Tires: Pneumatic (air-filled) tires, suitable for uneven surfaces.
Mast: Generally available with 2-stage or high-visibility masts.
Fuel System: Uses standard 8-gallon (33 lb) forklift propane tanks, which usually last for an 8-hour shift.
Usage and Maintenance:
Applications: Material handling in warehousing, manufacturing, and general logistics.
Components: Often features IMPCO propane conversion components and regulators.
Maintenance: Routine maintenance includes checking the propane regulator, hoses, and spark plugs.
Safety: The unit operates under LP gas safety classifications.

Used models are often available in the $20,000 - $35,000 range, though prices vary heavily based on condition and year.

This one is used but functions. It's brakes don't work well but the parking brake does. It has some fluid leaks.